Negative pressure therapy with dynamic profile capability

ABSTRACT

An apparatus and system for fluidly connecting a reduced-pressure source to a dressing and a method for manufacturing and using the same include a base having an aperture and a wall having a peripheral portion coupled to the base. The wall may form a cavity in fluid communication with the aperture. The apparatus also may include a conduit port fluidly coupled to the cavity and adapted to receive a conduit. The base may be adapted to couple to the dressing, and the wall may be adapted to collapse from a first position to a second position in response to a supply of reduced pressure from the reduced-pressure source.

Under 35 U.S.C. §119(e), this application claims priority to and thebenefit of U.S. Provisional Patent Application No. 61/784,797 filed Mar.14, 2013, entitled “Negative Pressure Therapy with Dynamic ProfileCapability,” the disclosure of which is hereby incorporated by referencein its entirety.

TECHNICAL FIELD

The present disclosure relates generally to systems, apparatuses, andmethods for providing negative pressure therapy to a tissue site. Moreparticularly, but not by way of limitation, the present disclosurerelates to a dressing connector having a dynamic profile.

BACKGROUND

Clinical studies and practice have shown that reducing pressure inproximity to a tissue site can augment and accelerate growth of newtissue at the tissue site. The applications of this phenomenon arenumerous, but is has proven particularly advantageous for treatingwounds. Regardless of the etiology of a wound, whether trauma, surgery,or another cause, proper care of the wound is important to the outcome.Treatment of wounds with reduced pressure may be commonly referred to as“reduced-pressure wound therapy,” but is also known by other names,including “negative-pressure therapy,” “negative pressure woundtherapy,” and “vacuum therapy,” for example. Reduced-pressure therapymay provide a number of benefits, including migration of epithelial andsubcutaneous tissues, improved blood flow, and micro-deformation oftissue at a wound site. Together, these benefits can increasedevelopment of granulation tissue and reduce healing times.

While the clinical benefits of reduced-pressure therapy are widelyknown, the profile of a dressing can be a limiting factor in itsapplication to some tissue sites. For example, many dressings arecoupled to a reduced-pressure source through a connection pad. Theprofile of a dressing and connection pad can cause significantdiscomfort or secondary damage to a tissue site if the tissue site bearsany weight of a patient, such as on a foot, a sacrum, or the back of abed-ridden patient. Thus, the development and operation ofreduced-pressure systems, components, and processes continues to presentsignificant challenges to manufacturers, healthcare providers, andpatients.

SUMMARY

According to an illustrative exemplary embodiment, an apparatus forfluidly connecting a reduced-pressure source to a dressing is described.The apparatus may include a base having an aperture and a wall having aperipheral portion coupled to the base. The wall forms a cavity in fluidcommunication with the aperture. The apparatus also may include aconduit port fluidly coupled to the cavity and adapted to receive aconduit. The base may be adapted to couple to the dressing, and the wallmay be adapted to collapse from a first position to a second position inresponse to a supply of reduced pressure from the reduced-pressuresource.

According to another illustrative exemplary embodiment, a system fortreating a tissue site with reduced pressure is described. The systemmay include a manifold adapted to be placed proximate to the tissue siteand a sealing member adapted to cover the manifold and a portion ofintact epidermis to form a sealed space. The system also may include areduced-pressure source adapted to supply reduced pressure to themanifold and a connector adapted to fluidly couple the reduced pressuresource to the manifold through the sealing member. The connector mayinclude a wall forming a cavity. The wall may be adapted to transitionbetween a first position and a second position in response to a supplyof reduced pressure. The connector also may include a conduit portadapted to fluidly couple the cavity to a conduit. The connector furthermay include a base extending from a peripheral portion of the wall andadapted to be coupled to the sealing member.

According to yet another illustrative exemplary embodiment, a method ofmanufacturing an apparatus for fluidly connecting a reduced-pressuresource to a dressing is described. A base having an aperture may beformed and a wall having a peripheral portion may be coupled to thebase. The wall may form a cavity in fluid communication with theaperture. A conduit port may be fluidly coupled to the cavity. Theconduit port may be adapted to receive a conduit. The base may beadapted to couple to the dressing, and the wall may be adapted tocollapse from a first position to a second position in response to asupply of reduced pressure from the reduced-pressure source.

According to still another embodiment, a method of treating a tissuesite with reduced pressure is described. A manifold may be disposedproximate to the tissue site, and a sealing member may be secured overthe manifold and a portion of intact epidermis to form a sealed space.The sealing member may have an opening formed therein. A connector maybe coupled to the sealing member proximate to the opening. Areduced-pressure source may be fluidly coupled to the connector tosupply reduced pressure to the manifold. The connector may include abase having an aperture and a wall having a peripheral portion coupledto the base. The wall may form a cavity in fluid communication with theaperture. The connector may further include a conduit port fluidlycoupled to the cavity and adapted to receive a conduit. The wall may beadapted to collapse from a first position to a second position inresponse to a supply of reduced pressure from the reduced-pressuresource. Reduced pressure may be supplied to the manifold through theconnector. At least a portion of the wall may be collapsed from thefirst position to the second position when a therapeutic reducedpressure may be reached in the sealed space.

Other aspects, features, and advantages of the illustrative exemplaryembodiments will become apparent with reference to the drawings anddetailed description that follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a reduced-pressure system for applicationof reduced pressure to a tissue site;

FIG. 2 is a top view of a connector of the reduced-pressure therapysystem of FIG. 1;

FIG. 3 is a bottom view of the connector of FIG. 2;

FIG. 4 is a perspective view of the connector of FIG. 2;

FIG. 5 is a sectional view of the connector taken along line 5-5 of FIG.2 in a first position;

FIG. 6 is a sectional view of the connector having a connector conduitfluidly coupled thereto;

FIG. 7 is another perspective view of the connector of FIG. 2;

FIG. 8 is a sectional view of the connector of the reduced-pressuretherapy system of FIG. 2 in a second position; and

FIG. 9 is a perspective view of the connector of FIG. 4.

DETAILED DESCRIPTION OF ILLUSTRATIVE EXEMPLARY EMBODIMENTS

New and useful systems, methods, and apparatuses for supplyingreduced-pressure to a tissue site with a low profile dressing are setforth in the appended claims. Objectives, advantages, and a preferredmode of making and using the systems, methods, and apparatuses may beunderstood best by reference to the following detailed description inconjunction with the accompanying drawings. The description providesinformation that enables a person skilled in the art to make and use theclaimed subject matter, but may omit certain details already well-knownin the art. Moreover, descriptions of various alternatives using termssuch as “or” do not necessarily require mutual exclusivity unlessclearly required by the context. Reference to “an” item refers to one ormore of those items. The claimed subject matter may also encompassalternative exemplary embodiments, variations, and equivalents notspecifically described in detail. The following detailed descriptionshould therefore be taken as illustrative and not limiting.

The example embodiments may also be described herein in the context ofreduced-pressure therapy applications, but many of the features andadvantages are readily applicable to other environments and industries.Spatial relationships between various elements or to the spatialorientation of various elements may be described as depicted in theattached drawings. In general, such relationships or orientations assumea frame of reference consistent with or relative to a patient in aposition to receive reduced-pressure therapy. However, as should berecognized by those skilled in the art, this frame of reference ismerely a descriptive expedient rather than a strict prescription.

FIG. 1 is a sectional view of one exemplary embodiment of a therapysystem 100 for supplying reduced pressure to a tissue site 102 having alow profile in accordance with this specification. As illustrated, thetherapy system 100 may include a dressing 104 fluidly coupled to areduced-pressure source 106. A regulator or controller may also befluidly coupled to the dressing 104 and the reduced-pressure source 106.

The term “tissue site” in this context broadly refers to a wound ordefect located on or within tissue, including but not limited to, bonetissue, adipose tissue, muscle tissue, neural tissue, dermal tissue,vascular tissue, connective tissue, cartilage, tendons, or ligaments. Awound may include chronic, acute, traumatic, subacute, and dehiscedwounds, partial-thickness burns, ulcers (such as diabetic, pressure, orvenous insufficiency ulcers), flaps, and grafts, for example. The term“tissue site” may also refer to areas of any tissue that are notnecessarily wounded or defective, but are instead areas in which it maybe desirable to add or promote the growth of additional tissue. Forexample, reduced pressure may be used in certain tissue areas to growadditional tissue that may be harvested and transplanted to anothertissue location.

The fluid mechanics of using a reduced-pressure source to reducepressure in another component or location, such as within a sealedtherapeutic environment, can be mathematically complex. However, thebasic principles of fluid mechanics applicable to reduced-pressuretherapy are generally well-known to those skilled in the art, and theprocess of reducing pressure may be described illustratively herein as“delivering,” “distributing,” or “generating” reduced pressure, forexample.

In general, exudates and other fluid flow toward lower pressure along afluid path. This orientation may generally be presumed for purposes ofdescribing various features and components of reduced-pressure therapysystems herein. Thus, the term “downstream” typically implies somethingin a fluid path relatively closer to a reduced-pressure source, andconversely, the term “upstream” implies something relatively furtheraway from a reduced-pressure source. Similarly, it may be convenient todescribe certain features in terms of fluid “inlet” or “outlet” in sucha frame of reference. However, the fluid path may also be reversed insome applications (such as by substituting a positive-pressure sourcefor a reduced-pressure source) and this descriptive convention shouldnot be construed as a limiting convention.

A reduced-pressure source, such as the reduced-pressure source 106, maybe a reservoir of air at a reduced pressure, or may be a manually orelectrically-powered device that can reduce the pressure in a sealedvolume, such as a vacuum pump, a suction pump, a wall suction portavailable at many healthcare facilities, or a micro-pump, for example.The reduced-pressure source may be housed within or used in conjunctionwith other components, such as sensors, processing units, alarmindicators, memory, databases, software, display devices, or userinterfaces that further facilitate reduced-pressure therapy. While theamount and nature of reduced pressure applied to a tissue site may varyaccording to therapeutic requirements, the pressure typically rangesbetween −5 mm Hg (−667 Pa) and −500 mm Hg (−66.7 kPa). Commontherapeutic ranges are between −75 mm Hg (−9.9 kPa) and −300 mm Hg(−39.9 kPa).

In general, components of the therapy system 100 may be coupled directlyor indirectly. For example, reduced-pressure source 106 may be directlycoupled to the regulator and indirectly coupled to the dressing 104through the regulator. Components may be fluidly coupled to each otherto provide a path for transferring fluid (i.e., liquid and/or gas)between the components. In some exemplary embodiments, components may befluidly coupled with a tube 108, for example. A “tube,” as used herein,broadly refers to a tube, pipe, hose, conduit, or other structure withone or more lumina adapted to convey fluid between two ends. Typically,a tube is an elongated, cylindrical structure with some flexibility, butthe geometry and rigidity may vary. In some exemplary embodiments,components may additionally or alternatively be coupled by virtue ofphysical proximity, being integral to a single structure, or beingformed from the same piece of material. Coupling may also includemechanical, thermal, electrical, or chemical coupling (such as achemical bond) in some contexts.

The dressing 104 generally may include a cover; such as a drape 110, anda tissue interface, such as a manifold 112. The drape 110 may be anexample of a sealing member. A sealing member may be constructed from amaterial that can provide a fluid seal between two components or twoenvironments, such as between a therapeutic environment and a localexternal environment. The sealing member may be, for example, animpermeable or semi-permeable, elastomeric material that can provide aseal adequate to maintain a reduced pressure at a tissue site for agiven reduced-pressure source. For semi-permeable materials, thepermeability generally should be low enough that a desired reducedpressure may be maintained to create a sealed therapeutic environment.An attachment device may be used to attach a sealing member to anattachment surface, such as an undamaged epidermis, a gasket, or anothersealing member. The attachment device may take many forms. For example,an attachment device may be a medically acceptable, pressure-sensitiveadhesive that extends about a periphery, a portion of, or an entirety ofthe sealing member. Other exemplary embodiments of an attachment devicemay include a double-sided tape, paste, hydrocolloid, hydrogel, siliconegel, organogel, or an acrylic adhesive.

The manifold 112 can be generally adapted to contact the tissue site102. The manifold may be partially or fully in contact with the tissuesite 102. If the tissue site 102 is a wound, for example, the manifold112 may partially or completely fill the wound, or may be placed overthe wound. The manifold 112 may take many forms, and may have manysizes, shapes, or thicknesses depending on a variety of factors, such asthe type of treatment being implemented or the nature and size of thetissue site 102. For example, the size and shape of the manifold 112 maybe adapted to the contours of deep and irregular shaped tissue sites.

More generally, a manifold may be a substance or structure adapted todistribute reduced pressure across a tissue site, remove fluid from atissue site, or both. In some exemplary embodiments, though, a manifoldmay also facilitate delivering fluid across a tissue site, if the fluidpath is reversed or a secondary fluid path is provided, for example. Amanifold may include flow channels or pathways that distribute fluidprovided to and removed from a tissue site around the manifold. In oneexemplary embodiment, the flow channels or pathways may beinterconnected to improve distribution of fluid provided to or removedfrom a tissue site. For example, cellular foam, open-cell foam, poroustissue collections, and other porous material, such as gauze or feltedmat, generally include structural elements arranged to form flowchannels. Liquids, gels, and other foams may also include or be cured toinclude flow channels.

In one exemplary embodiment, the manifold 112 may be a porous foammaterial having interconnected cells or pores adapted to uniformly (orquasi-uniformly) distribute reduced pressure to the tissue site 102. Thefoam material may be either hydrophobic or hydrophilic. In onenon-limiting example, the manifold 112 can be an open-cell, reticulatedpolyurethane foam such as GranuFoam® dressing available from KineticConcepts, Inc. of San Antonio, Tex.

In an example in which the manifold 112 may be made from a hydrophilicmaterial, the manifold 112 may also wick fluid away from the tissue site102, while continuing to distribute reduced pressure to the tissue site102. The wicking properties of the manifold 112 may draw fluid away fromthe tissue site 102 by capillary flow or other wicking mechanisms. Anexample of a hydrophilic foam may be a polyvinyl alcohol, open-cell foamsuch as V.A.C. WhiteFoam® dressing available from Kinetic Concepts, Inc.of San Antonio, Tex. Other hydrophilic foams may include those made frompolyether. Other foams that may exhibit hydrophilic characteristicsinclude hydrophobic foams that have been treated or coated to providehydrophilicity.

The manifold 112 may further promote granulation at the tissue site 102when pressure within the sealed therapeutic environment is reduced. Forexample, any or all of the surfaces of the manifold 112 may have anuneven, coarse, or jagged profile that can induce microstrains andstresses at the tissue site 102 if reduced pressure is applied throughthe manifold 112.

In one exemplary embodiment, the manifold may be constructed frombioresorable materials. Suitable bioresorbable materials may include,without limitation, a polymeric blend of polylactic acid (PLA) andpolyglycolic acid (PGA). The polymeric blend may also include withoutlimitation polycarbonates, polyfumarates, and capralactones. Themanifold 112 may further serve as a scaffold for new cell-growth, or ascaffold material may be used in conjunction with the manifold 112 topromote cell-growth. A scaffold may generally be a substance orstructure used to enhance or promote the growth of cells or formation oftissue, such as a three-dimensional porous structure that provides atemplate for cell growth. Illustrative examples of scaffold materialsinclude calcium phosphate, collagen, PLA/PGA, coral hydroxy apatites,carbonates, or processed allograft materials.

In operation, the manifold 112 may be placed within, over, on, orotherwise proximate to a tissue site, for example the tissue site 102.The drape 110 may be placed over the manifold 112 and sealed to tissueproximate to the tissue site 102. The tissue proximate to the tissuesite 102 may often be undamaged epidermis peripheral to the tissue site102. Thus, the dressing 104 can provide the sealed therapeuticenvironment proximate to the tissue site 102, substantially isolatedfrom the external environment, and the reduced-pressure source 106 canreduce the pressure in the sealed therapeutic environment. An openingmay be formed in the drape 110 so that the reduced pressure source 106may be fluidly coupled to the sealed therapeutic environment. Reducedpressure applied uniformly through the manifold 112 in the sealedtherapeutic environment can induce macrostrain and microstrain in thetissue site 102, as well as remove exudates and other fluid from thetissue site 102, which can be collected in the container 112 anddisposed of properly. In an exemplary embodiment, a filter 133 may bedisposed proximate to the opening to limit movement of liquid out of thesealed therapeutic environment.

“Reduced pressure” generally refers to a pressure less than a localambient pressure, such as the ambient pressure in a local environmentexternal to a sealed therapeutic environment provided by the dressing104. In many cases, the local ambient pressure may also be theatmospheric pressure at which a tissue site is located. Alternatively,the pressure may be less than a hydrostatic pressure associated withtissue at the tissue site. Unless otherwise indicated, values ofpressure stated herein are gauge pressures. Similarly, references toincreases in reduced pressure typically refer to a decrease in absolutepressure, while decreases in reduced pressure typically refer to anincrease in absolute pressure.

The therapy system 100 may also include a container 114. The container114 may be representative of a container, canister, pouch, or otherstorage component that can be used to manage exudates and other fluidwithdrawn from a tissue site. In many environments, a rigid containermay be preferred or required for collecting, storing, and disposing offluid. In other environments, fluid may be properly disposed of withoutrigid container storage, and a re-usable container could reduce wasteand costs associated with reduced-pressure therapy. In an exemplaryembodiment, the container 114 may include an absorbent member 116, afirst layer, such as a downstream layer 118, and a second layer, such asan upstream layer 120. The upstream layer 120 and the downstream layer118 envelop or enclose the absorbent member 116, which can absorb bodyfluid drawn by the reduced pressure through the upstream layer 120.

The absorbent member 116 may be formed of or include an absorbentmaterial. The absorbent material can hold, stabilize, and/or solidifyfluid that may be collected from the tissue site 102. The absorbentmaterial may be of the type referred to as “hydrogels,”“super-absorbents,” or “hydrocolloids.” When disposed within thedressing 104, the absorbent material may be formed into fibers orspheres to manifold reduced pressure until the absorbent member 116becomes saturated. Spaces or voids between the fibers or spheres mayallow a reduced pressure that is supplied to the dressing 104 to betransferred within and through the absorbent member 116 to the manifold112 and the tissue site 102. In some exemplary embodiments, theabsorbent material may be Texsus FP2325 having a material density of 800grams per square meter (gsm). In other exemplary embodiments, theabsorbent material may be BASF 402C, TAL 2317 available from TechnicalAbsorbents Limited, sodium polyacrylate super absorbers, cellulosics(carboxy methyl cellulose and salts such as sodium CMC), or alginates.

In some exemplary embodiments, the upstream layer 120 and the downstreamlayer 118 have perimeter dimensions that are larger than the perimeterdimensions of the absorbent member 116. When the absorbent member 116 ispositioned between the upstream layer 120 and the downstream layer 118and the center portions of the absorbent member 116, the upstream layer120 and the downstream layer 118 are aligned, the upstream layer 120 andthe downstream layer 118 extend beyond the perimeter of the absorbentmember 116. In some exemplary embodiments, the upstream layer 120, andthe downstream layer 118 surround the absorbent member 116. Peripheralportions of the upstream layer 120 and the downstream layer 118 arecoupled so that the upstream layer 120 and the downstream layer 118enclose the absorbent member 116. The upstream layer 120 and thedownstream layer 118 may be coupled by high frequency welding,ultrasonic welding, heat welding, or impulse welding, for example. Inother exemplary embodiments, the upstream layer 120 and the downstreamlayer 118 may be coupled by bonding or folding, for example.

The upstream layer 120 and the downstream layer 118 may each have afirst side and a second side. In some exemplary embodiments, the firstside and the second side may have different relative liquid affinitiesso that one side may be considered hydrophilic and the other side may beconsidered hydrophobic. The upstream layer 120 and the downstream layer118 may be formed of non-woven material having a thickness. In someexemplary embodiments, the upstream layer 120 and the downstream layer118 have a polyester fibrous porous structure. The upstream layer 120and the downstream layer 118 may preferably be non-perforated. Theupstream layer 120 and the downstream layer 118 may be formed ofLibeltex TDL2 or TL4, for example.

The hydrophobic side of the upstream layer 120 and the downstream layer118 are configured to distribute body fluid. The hydrophobic side mayalso be referred to as a wicking side, wicking surface, distributionsurface, distribution side, or fluid distribution surface. Thehydrophobic side may be a smooth distribution surface configured to movefluid through the upstream layer 120 and the downstream layer 118 alonga grain of the upstream layer 120 and the downstream layer 118,respectively, distributing fluid throughout the upstream layer 120 andthe downstream layer 118. The hydrophilic side may be configured toacquire fluid from the hydrophobic side to aid in fluid movement intothe absorbent member 116. The hydrophilic side may also be referred toas a fluid acquisition surface, fluid acquisition side, hydrophilicacquisition surface, or hydrophilic acquisition side. The hydrophilicside may be a fibrous surface and be configured to draw fluid into theupstream layer 120 and the downstream layer 118.

In some exemplary embodiments, the hydrophobic side may be disposedadjacent to the absorbent member 116. In other exemplary embodiments,the hydrophilic side may be disposed adjacent to the absorbent member116. In still other exemplary embodiments, the downstream layer 118 mayhave the hydrophilic side disposed adjacent to the absorbent member 116and the upstream side 120 may have the hydrophobic side adjacent to theabsorbent member 116. In yet other exemplary embodiments, the downstreamlayer 118 may have the hydrophobic side disposed adjacent to theabsorbent member 116 and the upstream side 120 may have the hydrophilicside adjacent to the absorbent member 116.

A reduced-pressure therapy system may also include a connector oradapter configured to fluidly couple a tube, such as the tube 108, to adressing, such as the dressing 104. A connector may include a flangeportion that couples to a dressing, and a port portion that fluidlycouples to a tube. The flange portion may fluidly couple the connectorto the dressing 104, for example, and the port portion may fluidlycouple the connector to the reduced pressure source. In this manner, theconnector may prevent fluid communication between the sealed therapeuticenvironment and the ambient environment, while allowing fluidcommunication between a tissue site and a reduced-pressure sourcethrough the dressing. A connector may also include a primary filterdisposed within a fluid channel. The primary filter may comprise ahydrophobic material substantially filling the fluid channel through theconnector and be adapted to limit passage of liquids through theconnector into a tube.

A connector may have an open area, such as a cavity, bounded by a flangeportion and fluidly coupled to a port portion. If the connector isdisposed on a dressing, the cavity may be aligned with an opening in thedrape so that fluid communication may occur between the tissue site andthe connector through the aperture. The cavity may provide the primaryfluid connection between a tube and a dressing, transitioning fluid flowbetween a manifold and an internal diameter of the tube.

Often, a manifold may be significantly larger than the diameter of atube. A connector, and specifically a cavity in the connector, canoperate to transition reduced pressure from a tube to a manifold, andtransition fluid drawn into the manifold to the tube. Preferably, thefluid transition occurs with as little restriction as possible so thatthe application of therapeutic reduced pressure is not undesirablyterminated. Consequently, reduced pressure supplied to a tissue siteshould be accommodated by a cavity, and the fluid removed from thetissue site should also be accommodated by the cavity.

For example, a cavity of a connector can channel a large volume of fluidfrom a tissue site that produces a large amount of fluid into a tube andat a flow rate high enough to avoid loss of reduced pressure. Inaddition, a cavity may have to accommodate movement of solids from atissue site into a container, again without causing a loss of reducedpressure at the tissue site. If fluid is retained in a dressing, forexample in the container 114, the portion of a cavity in fluidcommunication with a tissue site must have a sufficient surface area toensure that the therapeutic reduced pressure can be supplied to thetissue site. A cavity should also be able to accommodate sufficient flowto manage leaks, for example, between the drape 108 and the intactepidermis surrounding the tissue site 102. A cavity can provide thesefunctions with as little restriction to fluid flow between a tube and atissue site as possible to avoid undesired cessation of the applicationof reduced-pressure therapy.

As a cavity may be the fluid connection means between a tube and adressing, the cavity should be sufficiently large to avoid restrictingthe flow of fluid between a tissue site and a reduced-pressure source.Having a sufficiently sized cavity becomes more imperative where theflow of fluid, both of liquids from a tissue site to a reduced-pressuresource and of reduced pressure from the reduced-pressure source to thetissue site is continuous.

To provide an effective transition between a manifold and a tube, acavity may transition from a relatively large aperture disposedproximate to a manifold to a relatively small lumen of a tube. Such anaperture typically may have a diameter larger than the diameter of alumen but smaller than the exposed surface area of a manifold. In anexemplary embodiment, an aperture may have a diameter substantiallysimilar to the diameter of an opening formed in a drape that allows areduced-pressure source to be fluidly coupled to a sealed therapeuticenvironment. A cavity may have a shape that transitions an aperture to aport portion so that fluid may be encouraged to flow toward a lumen.Some connectors may have a domed-shape cavity, for example, which canextend greater than 5 mm in a vertical direction from a flange portion.In addition, a profile of a cavity may have a sharp change in profileheight from a flange portion of a connector to a wall of the connectorforming the cavity.

For low acuity systems, a container may be disposed adjacent a tissuesite between a manifold and a drape. Flow of fluid past such a containerduring reduced-pressure therapy may represent a failure of a connector.For example, if a continuous application of reduced pressure is requiredduring therapy, a drape may not be sealed to the undamaged epidermisproximate to a tissue site. In another example, if fluid, includingliquid, are moved through a connector during the application of reducedpressure, a filter disposed between the connector and a container maynot be retaining fluid in the container. In these situations, the fluidflow rate at the initiation of reduced pressure therapy may besignificantly higher than the flow rate once the sealed therapeuticenvironment may have reached a therapeutic reduced pressure.

A connector may have a profile that presents significant challenges totreating tissue sites located where a patient may rest upon the tissuesite, or that may be a weight-bearing tissue site, such as a pressureulcer on the foot, the back of a leg, a hip, or a buttock area, forexample. Relatively tall features of a connector on a dressing may causediscomfort if a patient places weight on a tissue site. The discomfortmay be caused in part by a connector being pressed into a tissue site bya patient's weight, for example. The discomfort may also be caused bythe application of compression therapy in addition to reduced-pressuretherapy, for example, for a patient with venous leg disease. In extremecases, a patient may experience secondary damage to a tissue site, forexample, where the pressure of a connector on the tissue site may causean ulcer, damage newly formed tissue, or create a pressure sore.

The potential for discomfort or secondary damage may discourage the useof beneficial reduced-pressure therapy if a tissue site is in aweight-bearing location. In other scenarios, a patient may requestdiscontinuation of reduced-pressure therapy because of the discomfort.Consequently, a significant group of patients that could benefit fromreduced-pressure therapy may be excluded. For example, in the PUPPS3Pressure Ulcer Survey in Australia in 2006, 25.2% of pressure ulcerswere on the heel, and 24.8% were on the sacrum, both examples ofweight-bearing locations. Clinicians and patients were reportedly notinclined to use reduced-pressure therapy in these weight-bearinglocations where a connector was expected to be uncomfortable andunconformable.

Generally, connectors have also been designed to resist collapse underreduced-pressure, which can ensure that a cavity continues to provide atransition between a tube and a manifold. In addition, a connector maystill have a profile that exhibits sudden sharp changes in height toaccommodate a cavity, for example, at locations of the connector where aflange portion transitions to a cavity portion. Thus, these connectorsmay still cause patient discomfort and potential pressure ulcers due tothe sudden sharp changes in profile height and material hardness.

As disclosed herein, the therapy system 100 can overcome theseshortcomings and others by providing a connector with a dynamic profile.For example, as illustrated in the exemplary embodiment of FIG. 1, thetherapy system 100 may include a connector 122. The connector 122 may bemolded such that an open cavity is provided if there is no pressuredifferential across the connector 122, but the cavity can collapse andassume a lower profile as therapeutic pressure is applied and increasesthe pressure differential. In more particular exemplary embodiments, theconnector 122 may have a wall adapted to change the geometric profile ofthe connector 122 in response to the application of reduced-pressure.The profile of the connector 122 may also revert back to the originalprofile if the differential pressure is equalized, such as if therapy isterminated. In general, the connector 122 may have a low profile with adynamic cavity wall to reduce the risk of patient discomfort orsecondary damage.

FIG. 2 is a top view illustrating additional details that may beassociated with some embodiments of the connector 122. The connector 122may include a base 124, a wall 126, and a conduit port 128. FIG. 3 is abottom view illustrating additional details that may be associated withsome embodiments of the connector 122. The base 124 may couple to thewall 126 as shown in the example embodiments of FIG. 2 and FIG. 3. Thewall 126 may include an interior surface that defines a cavity 130. Thebased 124 may have an aperture 132, and a peripheral portion of the wall126 may be coupled to the base 124 adjacent to the apeprture 132 so thatthe cavity 130 is in fluid communication with the apeture 132. FIG. 4 isa perspective view illustrating additional details that may beassociated with some embodiments of the connector 122. As shown in FIG.4, the wall 126 may be a generally semi-spherical structure having anexterior surface. The conduit port 128 protrudes from the exteriorsurface of the wall 126 and may include a lumen 134. The conduit port128 may be narrower proximate to the apex of the wall 126 and broaderproximate to the base 124 so that the conduit port may have a slightlypyramidal shape. Sides of the conduit port 128 may slope to the apex ofthe wall 126 from a first end 127 to a second end 129 so that theconduit port 128 may protrude from the wall 126 proximate to the base124. The sides of the conduit port 128 may taper as the sides of theconduit port 128 extend between the base 124 and the apex of the wall126.

FIG. 5 is a sectional view illustrating additional details that may beassociated with some embodiments of the connector 122. As shown in FIG.5, the base 124 may be a flange having at least a portion that issubstantially planar and adapted to couple to the dressing 104. In someexemplary embodiments, the base 124 may have a diameter of about 42 mm.In other exemplary embodiments, the base 124 may have a larger orsmaller diameter. In some exemplary embodiments, the base 124 may have athickness of about 1.25 mm. In some exemplary embodiments, the base 124may have a thickness in the range of about 0.60 mm to about 2.00 mm. Instill other exemplary embodiments, the thickness of the base 124 may begreater than about 2.00 mm or less than about 0.60 mm. The base 124 mayinclude an adhesive or other attachment device on a lower surface of thebase 124 so that the base 124 may be coupled to the drape 110.

The wall 126 may include peripheral portions that can be coupled to thebase 124 so that the base 124 extends outwardly away from the wall 126.The wall 126 may have a height relative to an upper surface of the base124 of about 3 mm. For example, the wall 126 may protrude about 3 mmfrom the upper surface of the base 124 to an apex of the wall 126. Thewall 126 may have a thickness of about 1.25 mm. In some exemplaryembodiments, the wall 126 may have a thickness in the range of about0.60 mm to about 2.00 mm. In still other exemplary embodiments, thethickness of the wall 126 may be greater than about 2.00 mm or less thanabout 0.60 mm. The thickness of the wall 126 may be substantially thesame from the peripheral portions where the wall 126 joins the base 124to the apex of the wall 126. In other exemplary embodiments, thethickness of the wall 126 may vary from the peripheral portions wherethe wall 126 joins the base 124 to the apex.

The aperture 132 in the base 124 may permit fluid communication into thecavity 130. The aperture 132 may be located proximate to the peripheralportions of the wall 126 and adjacent to the base 124. In some exemplaryembodiments, the aperture 132 may have a diameter of about 34 mm. Inother exemplary embodiments, the aperture 132 may have a diameter in therange of about 26 mm to about 34 mm. In still other exemplaryembodiments, the aperture 132 may have a diameter greater than about 34mm and less than about 26 mm. The filter 133 may be disposed within theaperture 132. The filter 133 may be a hydrophobic filter adapted tolimit movement of liquid into the cavity 130. The filter 133 may have athickness less than the thickness of the base 124. In some exemplaryembodiments, the filter 133 may be welded to the base 124.

The conduit port 128 may be fluidly coupled to the cavity 130 to providefluid communication with the cavity 130 through the wall 126. Theconduit port 128 may have the first end 127 proximate to a centerportion of the cavity 130 and the apex of the wall 126 and the secondend 129 that terminates at the wall 126 and proximate to the base 124.The illustrative conduit port 128 may include the lumen 134 extendingfrom the first end 127 to the second end 219 of the conduit port 128 andpermits fluid communication with the cavity 130 through the wall 126.For example, the tube 108 may be fluidly coupled to the cavity 130through the conduit port 128 so that reduced pressure may be supplied tothe cavity 130 through the lumen 134 of the conduit port 128. In someexemplary embodiments, the lumen 134 may have a diameter of about 2 mmand tapers from the second end 129 to the first end 127. In otherexemplary embodiments, the lumen 134 may have a diameter greater than orless than 2 mm and may not taper.

In some exemplary embodiments, the connector 122 may include one or morechannels formed on portions of the inside surfaces of the wall 126within the cavity 130 extending between the base 124 and the conduitport 128. These channels may direct the flow of fluid and exudates fromthe tissue site 102 and the manifold 112 to the conduit port 128.

The connector 122 may be made of a semi-rigid material capable ofcollapsing under a force. In some exemplary embodiments, the connector122 may be formed of a material having a durometer of about 68 Shore A.In other exemplary embodiments, the connector 122 may have a durometerlarger or smaller then 68 Shore A, for example, in the range of about 25Shore A to about 100 Shore A. In a non-limiting example, the connector122 may be made from a plasticized polyvinyl chloride (PVC) that isbis(2-ethylhexyl) phthalate (DEHP) free, for example Colorite P/N6877G-015. In another exemplary embodiment, the connector 122 may beformed of 0.007% plasticized PVC. In still other exemplary embodiments,the connector 122 may be made from polyurethane, cyclic olefin copolymerelastomer, thermoplastic elastomer, poly acrylic, silicone polymer, orpolyether block amide copolymer.

The thickness of the wall 126 and the durometer of the wall 126 areselected so that the wall 126 may be a dynamic component of theconnector 122. For example, the thickness of the wall 126 and thedurometer of the wall 126 are selected so that the wall 126 may have afirst position having a first profile as shown in FIG. 5. As shown inFIG. 5, the first position may form the cavity 130 having a first volumethat may be adapted to permit a fluid flow rate sufficient to providethe therapeutic reduced pressure at the manifold 112 if the connector122 is disposed proximate to the dressing 104. The process of reducingpressure within the sealed therapeutic environment may be commonlyreferred to as “drawing down” a dressing. The first profile may extendvertically from the base 124 then slope horizontally toward the apex ofthe wall 126 proximate to the conduit port 128.

FIG. 6 is a sectional view illustrating additional details that may beassociated with some embodiments of the connector 122. As shown in FIG.6, the connector 122 may include a connector conduit 136. The connectorconduit 136 may be a tube similar to the tube 108 having a first endadapted to be inserted into the lumen 134 of the conduit port 128 and asecond end adapted to be inserted into a lumen of the tube 108. Theconnector conduit 136 may be more rigid than the tube 108 to limitbending of the connector conduit 136 proximate to the port 128 and toreduce instances of restriction proximate to the connector 122. Inaddition, the connector conduit 136 may have a smaller outer diameterthan the tube 108. In an exemplary embodiment, the connector conduit 136may have a diameter of about 2 mm. The diameter of the connector conduit136 may be selected to reduce patient discomfort if the connectorconduit 136 is disposed proximate to a tissue site at a weight-bearinglocation. In some exemplary embodiments, the diameter of the connectorconduit 136 may be about the same as the height of the connector 122from the top of the base 124 to the apex of the wall 126.

FIG. 7 is a perspective view illustrating additional details that may beassociated with some embodiments of the connector 122. As shown in FIG.7, the wall 126 may be in the first position so that the cavity 130 hasthe first volume that permits fluid flow between a tissue site and areduced pressure source. The connector 122 provides the cavity 130having the first volume permitting a first flow rate if areduced-pressure less than the therapeutic reduced pressure is applied.The first volume may permit flow of fluid and reduced pressure in arelatively unrestricted manner so that the dressing 104 may be drawndown.

FIG. 8 is a sectional view illustrating additional details that may beassociated with some embodiments of the connector 122. The wall 126 isshown in a second position having a second profile. Once the dressing isdrawn down, as described above, the wall 126 can collapse, at leastpartially, to the second position. If the dressing is drawn down and thewall 126 at least partially collapses, at least a portion of the wall126 may be proximate to the aperture 132. In some exemplary embodiments,at least a portion of the interior surface of the wall 126 in the secondposition may be located in a same horizontal plane as the lower surfaceof the base 124. Collapse of the wall 126 to the second position reducesthe volume of the cavity 130. The second profile of the wall 126 mayextend horizontally from the base 124, sloping toward the conduit port128. Generally, if the wall 126 is in the second position a substantialportion of the profile of the connector 122 may have a height the sameas the thickness of the wall 126. In some exemplary embodiments, theprofile slopes from a height of about 1.25 mm to a height of about 4.25mm. In some exemplary embodiments, the fluid connection between themanifold 112 and the reduced-pressure source 106 may be severed when thewall 126 is in the second position.

The durometer and the thickness of the wall 126 may be selected so thatthe wall 126 collapses from the first position to the second position atdesired levels of therapeutic reduced pressure. In an exemplaryembodiment, the durometer may be about 68 Shore A and the thickness ofthe wall 126 may be about 1.25 mm. In another exemplary embodiment, theconnector 122 may be formed of a 0.007% plasticized PVC; thus, thedurometer of the connector 122 may be held constant. The thickness ofthe wall 126 may then be selected based on the desired profile heightreduction under a therapeutic reduced pressure, for example 125 mmHg. Insome exemplary embodiments, if a profile height reduction between thefirst position and the second position of about 5.25 mm is desired, thethickness of the wall 126 may be about 0.6 mm. In other exemplaryembodiments, if a profile height reduction between the first positionand the second position of about 1.25 mm is desired, the thickness ofthe wall 126 may be about 1.25 mm. In still other exemplary embodiments,if a profile height reduction between the first position and the secondposition of about 0.75 mm is desired, the thickness of the wall 126 maybe about 1.85 mm.

FIG. 9 is a perspective view illustrating additional details that may beassociated with some embodiments of the connector 122. As shown in FIG.9, the wall 126 may have collapsed to the second position so that thecavity 130 has the second volume, substantially reducing the profile ofthe connector 122. If the dressing 104 has been drawn down and thesealed therapeutic environment has reached the therapeutic reducedpressure, the wall 126 may collapse to the second position having thesecond profile, reducing the volume of the cavity 130. If thetherapeutic reduced pressure has been reached in the sealed therapeuticenvironment, the flow rate of fluid through the connector 122 cansignificantly decrease; consequently, the reduced volume of the cavity130 with the wall 126 in the second position may not restrict fluidflow. The connector 122 may have a lower profile than conventionalconnectors, while permitting unrestricted fluid communication during theapplication of reduced pressure. In addition, the connector 122 may havea profile that reduces sudden changes in profile elevation, decreasingdiscomfort for a patient. If the application of reduced pressure ceases,or there is a need to supply additional reduced pressure, the connector122 may return to the first position of FIG. 5, FIG. 6, and FIG. 7. Forexample, if the amount of reduced pressure supplied to the connector 122decreases, or if a leaking drape 110 raises the absolute pressure in thesealed therapeutic environment, the wall 126 may expand to the firstposition. This expansion returns the connector 122 to the first profileto provide a large volume cavity 130 for the unrestricted flow ofreduced pressure. The supply of reduced pressure may then be increasedto re-pressurize the sealed therapeutic environment. In some exemplaryembodiments, the wall 126 may be in the second position duringapproximately 90% of its use.

In some exemplary embodiments, the connector 122 may provide anindication that the therapeutic reduced pressure has been reached. Forexample, as the thickness and the durometer of the wall 126 may beselected so that the wall 126 collapses at a known therapeutic reducedpressure, the connector 122 may be visually monitored during thedraw-down process. An operator or user can observe that the therapeuticreduced pressure has been reached by the collapse of the wall 126.Similarly, the wall 126 may be visually monitored to determine if thewall 126 is in the first position or the second position to determinewhether the tissue site 102 is being provided with therapeutic reducedpressure.

In other exemplary embodiments, a pressure sensor may be included in theconnector 122 to measure the pressure provided to the cavity 130. Insome exemplary embodiments, the pressure sensor may include a pressuresensing lumen routed through the conduit port 128 and fluidly coupled tothe reduced pressure source 106.

In some exemplary embodiments, the connector 122 may be used withinstillation therapy. For example, the connector 122 may permit anunrestricted flow of fluid during the application of instilling fluid,an unrestricted flow of fluid during withdrawal of the instilling fluid,and then a restricted flow following removal of all instilling fluid.

The systems and methods described herein may provide significantadvantages, some of which have already been mentioned. For example, thetherapy system 100 may be particularly advantageous for low-acuitywounds, which typically have sustained fluid flow at the beginning oftherapy when a dressing is evacuated. Thereafter, only minimal fluidflow may be anticipated for low-acuity wounds. Thus, a low-acuity woundtypically may have two different and contradictory flow conditionsduring the course of therapy. Initially, a low-acuity wound may need aconnector that may be relatively large and open to flow duringdraw-down, but may benefit significantly from a connector with a reducedprofile when flow is reduced after draw down. The therapy system 100provides a connector with a dynamic profile that can satisfy both ofthese flow conditions, and may be used on a tissue site atweight-bearing locations while reducing or substantially eliminatingdiscomfort and secondary damage to the tissue site. The operatingprinciple of the therapy system 100 may be extended to connectors whichprovide active fluid removal such as with connectors configured to havea canister for collecting fluid between the connector and the reducedpressure source. The connector may be fluidly coupled to the manifoldand the amount of profile height reduction may be selected to maintain afluid flow when the pad collapses. Similarly, the connector durometerand thickness may be selected to allow for use with instillation systemsto both supply and withdraw instilling fluid.

It should be apparent from the foregoing that an invention havingsignificant advantages has been provided. Any feature that is describedin connection to any one exemplary embodiment may also be applicable toany other exemplary embodiment, and the benefits and advantagesdescribed above may relate to one exemplary embodiment or may relate toseveral exemplary embodiments. While shown in only a few forms, thesystems and methods illustrated are susceptible to various changes andmodifications without departing from the scope of the claims.

We claim:
 1. An apparatus for fluidly connecting a reduced-pressuresource to a dressing, the apparatus comprising: a base having anaperture; a wall having a peripheral portion coupled to the base to forma cavity, wherein the aperture is configured to provide fluidcommunication between the cavity and the dressing; a conduit portcoupled to the wall and having a lumen fluidly coupled to the cavity;and a connector conduit having a first end adapted to be received in thelumen of the conduit port and a second end adapted to be mated with atube for delivering reduced-pressure; wherein the base is adapted tocouple to the dressing and the wall is adapted to collapse from a firstposition providing a first volumetric flow rate through the cavity at aflow velocity to a second position providing a second volumetric flowrate through the cavity while maintaining the flow velocity in responseto a change in a supply of reduced pressure from the reduced-pressuresource.
 2. The apparatus of claim 1, wherein the wall has a thickness ina range of about 0.60 mm to about 2.00 mm.
 3. The apparatus of claim 1,wherein the wall has a thickness of about 1.25 mm.
 4. The apparatus ofclaim 1, wherein the wall comprises a polymer having a durometer in arange of about 25 Shore A to about 100 Shore A.
 5. The apparatus ofclaim 1, wherein the wall comprises a polymer having a durometer ofabout 68 Shore A.
 6. The apparatus of claim 1, wherein the wallcomprises a polymer having a durometer in a range of about 25 Shore A toabout 100 Shore A and a thickness in a range of about 0.60 mm to about2.00 mm.
 7. The apparatus of claim 1, wherein the wall comprises apolymer having a durometer and a thickness so that the wall isconfigured to collapse from the first position to the second positionunder reduced pressure.
 8. The apparatus of claim 1, wherein the wallhas a sloping profile when the wall is in the second position.
 9. Theapparatus of claim 1, wherein the cavity has a first volume when thewall is in the first position and a second volume when the wall is inthe second position.
 10. The apparatus of claim 1, wherein the cavityhas a first volume when the wall is in the first position, a secondvolume when the wall is in the second position, and the first volume isgreater than the second volume.
 11. The apparatus of claim 1, whereinthe cavity has a height from a top of the base to a top of the wall ofabout 3 mm.
 12. The apparatus of claim 1, wherein the base has adiameter of about 34 mm.
 13. The apparatus of claim 1, furthercomprising an adhesive coupled to the base and adapted to couple thebase to the dressing, the adhesive adapted to create a fluid sealbetween the base and the dressing.
 14. The apparatus of claim 1, whereinthe wall and the base comprise polyvinyl chloride.
 15. The apparatus ofclaim 1, wherein the connector conduit comprises a rigidity that isgreater than a rigidity of the tube.
 16. The apparatus of claim 1,wherein when the wall is in the second position, the wall extendshorizontally from the base while sloping to the conduit port.
 17. Theapparatus of claim 1, wherein when the wall collapses from the firstposition to the second position, the wall is configured to change across-sectional area of a flow path through the cavity to maintain theflow velocity.
 18. A method of manufacturing an apparatus for fluidlyconnecting a reduced-pressure source to a dressing, the methodcomprising: forming a base having an aperture; coupling a wall to thebase adjacent to the aperture to form a cavity, wherein the aperture isconfigured to provide fluid communication between the cavity and thedressing; and fluidly coupling a conduit port to the wall and having alumen fluidly coupled to the cavity; providing a connector conduithaving a first end adapted to be received by the lumen of the conduitport and a second end adapted to mate with a tube for delivering reducedpressure; wherein the base is adapted to couple to the dressing and thewall is adapted to collapse from a first position providing a firstvolumetric flow rate through the cavity at a flow velocity to a secondposition providing a second volumetric flow rate through the cavitywhile maintaining the flow velocity in response to a change in a supplyof reduced pressure from the reduced-pressure source.
 19. The method ofclaim 18, wherein the method further comprises forming the wall with athickness in a range of about 0.60 mm to about 2.00 mm.
 20. The methodof claim 18, wherein the method further comprises forming the wall witha thickness of about 1.25 mm.
 21. The method of claim 18, wherein themethod further comprises forming the wall from a polymer having adurometer in a range of about 25 Shore A to about 100 Shore A.
 22. Themethod of claim 18, wherein the method further comprises forming thewall from a polymer having a durometer of about 68 Shore A.
 23. Themethod of claim 18, wherein the method further comprises forming thewall from a polymer having a durometer in a range of about 25 Shore A toabout 100 Shore A and a thickness in a range of about 0.60 mm to about2.00 mm.
 24. The method of claim 18, wherein the method furthercomprises forming the wall from a polymer having a durometer and athickness so that the wall collapses from the first position to thesecond position under reduced pressure.
 25. The method of claim 18,wherein coupling the wall having a peripheral portion to the basefurther comprises coupling the wall to the base so that the cavity has aheight from a top of the base to a top of the wall of about 3 mm. 26.The method of claim 18, wherein forming the base further comprisesforming the base with a diameter of about 34 mm.
 27. The method of claim18, wherein the method further comprises coupling an adhesive to thebase and adapted to couple the base to the dressing, the adhesivefurther adapted to create a fluid seal between the base and thedressing.
 28. The method of claim 18, wherein the method furthercomprises forming the wall and the base from polyvinyl chloride.
 29. Themethod of claim 18, wherein the connector conduit comprises a rigiditythat is greater than a rigidity of the tube.
 30. The method of claim 18,wherein when the wall is in the second position, the wall extendshorizontally from the base while sloping to the conduit port.
 31. Themethod of claim 18, wherein when the wall collapses from the firstposition to the second position, the wall is configured to change across-sectional area of a flow path through the cavity to maintain theflow velocity.